1. Field of the Invention
This invention is related to the use of a porous filter that is supported at the top of a rain gutter to prevent entry of solid debris into the rain gutter while allowing rain water to flow thought the porous filter into the relatively unobstructed gutter. More specifically this invention is directed to the use of porous foam or a reticulated foam for the filter and the use of a support member to position the foam filter on top of the gutter leaving the rain gutter largely unobstructed.
2. Description of the Prior Art
There are a number of devices that are employed to prevent solid debris, such as leaves, pine needles, twigs and litter from entering a rain gutter and clogging the gutter. There are a number of shields or filters that are employed to prevent entry of solid debris, but allow water to pass over the filter or shield and enter the gutter. Alternatively some prior art techniques employ a porous filler or filter material that can be inserted into and at least partially fill the gutter. The porous filler material will be liquid permeable so that rain water can flow through the material and in the rain gutter. The pores or openings in such materials are, however, sufficient small to prevent the entry of solid debris that is not dissolved in the rain water or in liquid flowing into the gutter. The solid debris will then accumulate on top of the filler material where it will normally be removed by the wind or by gravity.
U.S. Pat. No. 3,855,132 discloses the use of a porous polyurethane foam to fill a rain gutter. Rain water will flow through a sufficiently porous foam filling the rain gutter, but debris, such as leaves and paper scraps remain on the upper surface of the foam filler and cannot enter the rain gutter where clogs typically form. Supports can be provided along the length of the foam filler to leave an open passageway beneath the foam filler and above the bottom of the rain gutter.
US Patent Application Publication 2005/0034376 discloses the use of a porous sponge-like filler materials, such as fibers or foam or non-woven materials that can be cut to shape and packed into the gutter.
US Patent Application Publication 2005/0247611 discloses the use of a thick mat formed from a nonwoven material including randomly oriented and interconnected fibers or filaments forming open interstices affixed by a binder or coating. This mat is inserted into a rain gutter and in some cases in conjunction with a filter will prevent twigs, pine needles etc. from entering the rain gutter. Openings may be formed between the porous mat and bottom or side surfaces of the gutter to permit flow beneath the mat insert. U.S. Pat. No. 7,208,081 shows a similar gutter filler in which the foam filter material partially fills the gutter.
Even thought these gutter filler products are porous, they still can restrict the flow in a gutter, and because they must fill a substantial volume of the gutter, they can be relatively bulky and will use a significant amount of a material. It may also be difficult to install these products on rain gutters because roofing shingles may partially obstruct the rain gutters and gutter hangers can present obstructions.